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Theorem 1p1e2 8870
Description: One plus one equals two. Using proof-shortening techniques pioneered by Mr. Mel O'Cat, along with the latest supercomputer technology, Prof. Loof Lirpa and colleagues were able to shorten Whitehead and Russell's 360-page proof that 1+1=2 in Principia Mathematica to this remarkable proof only two steps long, thus establishing a new world's record for this famous theorem. (Contributed by Prof. Loof Lirpa, 1-Apr-2008.)
Assertion
Ref Expression
1p1e2 |- (1 + 1) = 2

Proof of Theorem 1p1e2
StepHypRef Expression
1 df-2 6031 . 2 |- 2 = (1 + 1)
21eqcomi 1526 1 |- (1 + 1) = 2
Colors of variables: wff set class
Syntax hints:   = wceq 997  (class class class)co 4021  1c1 5300   + caddc 5302  2c2 6022
This theorem was proved from axioms:  ax-1 4  ax-2 5  ax-3 6  ax-mp 7  ax-gen 1004  ax-4 1014  ax-5o 1016  ax-ext 1504
This theorem depends on definitions:  df-bi 154  df-an 232  df-cleq 1515  df-2 6031
Copyright terms: Public domain